In an internal combustion engine for e.g. an automobile, there sometimes is provided a valve timing control apparatus for controlling opening/closing timings of an intake valve or an exhaust valve, in accordance with driving conditions. This valve timing control apparatus is generally attached to one end of a cam shaft. Further, an auxiliary equipment such as a vacuum pump, a fuel pump, etc. is attached as a driven device driven by the internal combustion engine. These instruments sometimes are attached to one end of the cam shaft so as to reduce the total height of the internal combustion engine.
For instance, Patent Document 1 identified below discloses a construction for connecting a drive shaft of a driven device such as a fuel pump to one end of a cam shaft of an internal combustion engine. In this construction, a substantially cylindrical pump side coupling is attached with a nut to an end of the drive shaft located approximately at the center of the fuel pump. And, between a flange portion formed at one end of the cam shaft and the pump side coupling, there is interposed, as an intermediate member, a coupling constituting an Oldham's coupling, so that power is transmitted from the cam shaft and the drive shaft disposed substantially in series.
Patent Document 1: Japanese Patent Application “Kokai” No. 2001-263025 (page 3, FIGS. 1-3).